Certificate of need (CON) is a state-administered regulatory program requiring providers to obtain approval before establishing certain clinical services. A key focus on CON has been revascularization (coronary artery bypass graft surgery [CABG] and percutaneous coronary intervention [PCT]), which proliferated during the 1990s as a treatment for ischemic heart disease. In 1984, federal legislation that mandated CON for all states was repealed. Since then, 25 states have repealed CON for cardiac surgery and cardiac catheterization. There is some evidence that repeal of Con for revascularization may lead to dramatic rises in the number of new programs. However, the impact of the repeal of CON on the overall use of revascularization and on outcomes in older adults has not been adequately investigated. The proposed study will: [unreadable] [unreadable] Determine relationships between CON and use of coronary revascularization for patients admitted for Acute Myocardial Infarction (AMI). [unreadable] [unreadable] Determine relationships between CON and outcomes of patients admitted for AMI. [unreadable] [unreadable] The 12-month retrospective cohort study will examine consecutive patients 68 years and older admitted to all non-federal hospitals in the US for the treatment of acute myocardial infraction (AMI) during 1994 through 2002. The study will involve secondary analyses of Medicare administration data (MedPAR and Denominator Files). In addition, several other publicly available databases will be used to assess the stringency and scope of the individual CON programs and to control for hospital and market-level factors that may influence each endpoint and be endogenous with CON (e.g., hospital competition, managed care penetration, physician specialty). [unreadable] [unreadable] Study endpoints will include: 1) use of revascularization 30,90,365 days after admission for AMI and time to revascularization; 2) death within 30,90, or 365 days and time to death; and 3) readmission for ischemic heart disease within 30,90, or 365 days and time to readmission. The impact of CON on each endpoint will be evaluated using multivariable models that control for patient, hospital, and market factors. Analyses will account for clustering of patient within hospitals and markets using generalized mixed models for dichotomous outcomes (e.g., revascularization, mortality) and Cox regression with stratification for time-to-event outcomes (e.g., time to readmission). [unreadable] [unreadable]